In my day job I work as an auditor at a CPA firm and one of the audit clients that I work on happens to be my water district. During the recent audit, we the auditors were treated to a tour and shown the inner workings of the water treatment plant. At one point the manager showed us that the water flowing in a part of the plant exceeded drinking water standards. But it wasn’t done there. After that point the water was sent through about 8 feet of filters. Charcoal filters. I went home and tested the tap water at my house with my handy dandy TDS meter. I measured the tap water, the brita filter water, and my charcoal filtered tap water. Brita measured 36, Charcoal was 39, and tap water was 47. The water at my last house in Tallahassee was very bad for tea. The TDS was 155 and it just wasn’t suitable for tea at all. So I admit I made the silly misjudgment that all tap water was bad and never even bothered trying the tap water here in Spartanburg. I tasted it and it was pretty good, much better than Tallahassee. But it still had that chlorine taste to it.
Fast forward a few weeks and I am reading a book called How to Make Tea by Brian Keating and in the part about water it mentioned that if you let your tap water sit out overnight, the chlorine in it will dissipate. How have I never heard or read this before? After reading this I knew a new water test was necessary.

I wanted to try my charcoal filtered tap water, my tap water that has been sitting in the fridge for 24 hours, and Brita filtered water. The red one is an old pitcher that no longer has a filter in it.
The tea I used was Huang Shan Mao Feng or Yellow Mountain green tea. 3 grams per 100 ml and 175 degree water for all three. Porcelain gaiwans and porcelain cups to make it as fair as I could with what I had.


This test surprised me. I started with new TDS readings on all three waters. The brita was 33, the charcoal was 38 and the tap water was…. 38. Wait, what? The tap water was the same as the charcoal water and it was reduced by 9 from the fresh tap water reading. Maybe the chlorine really did dissipate over night.
So let’s get to it already. The winner, but every so slightly was the charcoal water. But the surprising part is that the tap water came in second, and the Brita was third. I really struggled coming up with any kind of tasting notes on this. All I really noticed was that the Brita was flat. It wasn’t bad but it was flatter than the other two. On the tap water, I could taste just a tiny hint of chlorine on the back and only on the top of my mouth, which I thought was strange. The charcoal didn’t have the chlorine taste at all and it had just a bit more depth to it. I know depth is a fancy tasting word and I wish I had a better way to describe it, but it just had more flavor, more tea flavor.
I had to get really nitpicky to pick a winner. If I tasted these blind, I’m not sure I could have told you the difference between the charcoal and the tap water. And that feels like a win for the tap water. Kudos to the Woodruff-Roebuck Water District.
This has also raised more questions. Like is the charcoal filter really adding anything or is the key just letting the water sit. I always let the water sit in the charcoal at least 24 hours before using it for tea. This particular batch had been in there for about 60 hours. This test wasn’t super scientific. Is my charcoal past its filtering life or does it need to be reactivated? I need to try with all the variables the same and a new charcoal filter.
A note on TDS. TDS stands for total dissolved solids. It will tell you how much of solids have dissolved into your water in a reading of parts per million or ppm. It does not however, tell you what is dissolved in your water. The tap water may have chlorine whereas the charcoal water may have a more desirable mineral in it. I would like to know that part but would probably need a chemistry lab to tell.

According to the back on the TDS meter, a 47 for tap water is pretty dang good! Ideal, actually.
If you don’t like your tap water, let it sit for a day or two and try again. My wife will be glad this is over and I won’t have three pitchers of tea water taking up half the fridge 🙂 Cheers!
Interesting stuff. I use an Electrolux water filter jug, and can really taste the difference in my tea when it’s time to change the filter cartridge (we have very heavy water here).
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This is fascinating! I’ve never noticed much of a difference in Singapore, but I suppose it’s because our water isn’t that hard. I guess past a certain standard of water, the quality of tea won’t improve that significantly?
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